Gardening Articles: Flowers :: Annuals

The Other Pollinators

by Amy Bartlett Wright

Nature has many wild workers. When watching insect activity around my flowers last spring, I missed the honeybees but hoped they would come buzzing around. I saw very few, because--as I found out later--their population had been devastated by a mite, but as I watched for them, I made a wonderful observation: plenty of pollinating was still going on. My flowers were blooming, my vegetables fruiting. What was doing it?

I saw many other kinds of bees: robust hairy bumblebees, small mining bees, and leafcutter bees. Metallic-hued sweat bees, bee-mimicking flies, butterflies, and beetles were also hard at work. I began to realize what was happening. Though beekeepers' colonies had been handling pollination, when mites afflicted the honeybees, nature sent in its second-stringers, and bountiful harvests still came in.

How Does Pollination Happen?

Pollination, a fortunate by-product of insects' nectar feeding and pollen collecting, is essential to the continued existence of many plants. When insects reach for the sweet juice of flowers that they need for food, they walk all over the flower parts, actively and passively collecting pollen and transporting it to other flowers.

Pollination is a necessary prerequisite to fertilization; without it, a plant will not set seed or fruit. It occurs when insects move pollen from the (male) anther of one flower to the (female) stigma of another flower. Two-thirds of all flowering plants depend on pollinating insects for this service. More than 3,800 species of bees exist in the United States, and most of them collect nectar and pollen. All adult bees eat protein-rich pollen and feed it to their young. In addition to insects, some birds, bats, and other mammals pollinate. Wind and water also transport pollen, but my focus here is on insect pollinators.

In recent years, the Varroa mite destroyed honeybee populations in many regions of the Northeast and central Midwest (Illinois, Iowa, Kansas, and Nebraska). Foulbrood, a bacterial infection that kills bees' larvae, and several other diseases and parasites also afflict colonies, despite the worker bees' attempts to remove infested brood in the hive (scientists call this hygienic behavior). When honeybee populations suffer, honey production goes down, and pollination of cultivated crops is in jeopardy. While it's important to care for and encourage honeybees, it's also important to understand that there are many other pollinators.

A Guide to the Pollinator Bees

Besides honeybees, pollinators include several other bee species, as well as insects that have filled the gap left by dwindling honeybee populations.